I'm more than satisfied with spending a week in Tanny's apartment in the middle of Dec., 22. The studio is beautiful, clean, had all the required amenities and provides nice views on Bangkok's skyline. The building is a centrally located condo in a very calm (you never meet crowds of tourists there) neighborhood with its own gym and pool.
As regards transport: you can get to Chong Nonsi BTS by using the BRT (fast bus with a separate lane), which usually goes every 15 mins.
Tanny, on the other hand, was very responsive and helpful.
Overall, I'll definitely book it again the future, if I'm to return to Bangkok.